Part of the enjoyment of investing in quality stereo equipment is being able to reproduce music as faithfully as possible. People invest in vinyl LPs because they sound richer, fuller, and simply better than CDs or compressed MPEG files.
Making the most of your vinyl record collection starts by connecting your turntable to the correct input to maximize the fidelity of the sound being reproduced. Many preamps are designed with a phono connection on the back panel to boost the signal of vinyl records specifically.
The phono stage of a preamp is designed for connecting a turntable (record player) that uses a phono cartridge to play vinyl records. Vinyl records have a unique audio signal characteristic due to the physical grooves and how the stylus of the turntable’s cartridge reads those grooves. This signal needs to be properly equalized and amplified before it can be sent to your speakers or headphones. This is why you don’t see turntables with direct inputs for speakers or headphones. The turntable’s sole function is to turn the records at a steady, constant speed and to accurately convey the signals in the grooves of a record to an outside preamp or amplification source.
The main function of a preamp is to boost those signals and provide as equal a level as possible of the fidelity achieved in the original recording. Here’s when and why you should use the phono input on a preamp:
Turntable Signal Level
The output signal from a typical phono cartridge is much lower than that of other audio sources like CD players, streaming devices, or media players. The phono connection on a preamp applies the necessary amplification to bring this low-level signal up to a line-level signal that your audio system can process accurately.
Vinyl records are cut with a specific equalization curve called the RIAA curve. This curve compensates for the way low frequencies are attenuated and high frequencies are boosted during the record-cutting process. The phono stage input on a preamp includes an RIAA equalization circuit to reverse this curve, ensuring that the audio you hear from your speakers is faithful to the original recording.
Phono cartridges have a unique impedance that needs to be correctly matched with the input impedance of the phono stage in the preamp. The phono connection is designed to provide the correct impedance for the cartridge, allowing for optimal signal transfer and minimal distortion.
Avoiding Sound Quality Issues
If you were to connect a turntable directly to a standard line-level input on an amplifier or receiver, the resulting audio would likely sound thin and lacking in bass, and the overall quality would be poor due to the lack of proper amplification and equalization. This is because the line-level input lacks the RIAA equalization. If you notice a noticeable drop in the fidelity of your music after you’ve moved your equipment around, check the connection to ensure your turntable is connected to the phono stage input as the first step in troubleshooting.
Value of Preamps
You should use the phono stage input on a preamp whenever you’re connecting a turntable that uses a phono cartridge to play vinyl records. If you’re using a different audio source, like a CD player or a digital media player, you should use a different line-level input on the preamp or amplifier. If your preamp or amplifier doesn’t have a dedicated phono input, you can use an external phono preamp (also called a phono stage) to process the turntable’s signal before sending it to a line-level input on your audio system.
Stereo Preamp from ADCOM
Be well-equipped to reproduce both digital and analog music formats with the GFP-915 wide bandwidth stereo preamplifier from ADCOM. This new preamp offers DVD audio and SACD formats that can support a wider frequency spectrum (100Hz) and dynamic range (144dB) than the conventional CD player. The GFP-915 is also equipped with a processor loop, tape loop, and a phono connection, making it the perfect addition to achieve a versatile stereo setup capable of faithfully reproducing music recorded on a variety of formats.
If you have any questions about the GFP-915 preamp or any of our other quality products, please feel free to contact us directly.